The present invention relates generally to the field of safety devices for forklifts, and more particularly to an easy to view indicator that shows the relative angle between the forks of the forklift and level ground.
Many times when operating a forklift (or “towmotor”) it is desirable to have the forks level, that is oriented so as to be parallel to level ground. Often times, the forklift operator relies on direct physical observation of the forks to determine if the forks are level. However, it is not uncommon for the operator's view of the forks to be obscured by the forklift's mast, intervening cables, the cargo to be lifted, or other items. Further, when the mast is extended such that the forks are located significantly above the operator, or the forks are placed very close together, or the forklift is on a slope, the resulting perspective view often makes it very difficult for the operator to properly judge the angle of the forks. And, if the operator is forced to exit the forklift so as to view the forks from the side, assuming such is possible, this process is plainly inefficient.
A number of approaches have been proposed for providing the forklift operator with a better indication of the levelness of the forks. For instance, a complex mechanical linkage is proposed in U.S. Pat. No. 5,697,755 to McCauley et al. The McCauley approach is somewhat of an improvement, but McCauley's mechanical linkage system is both complex and difficult to see from the typical operating position. Another approach is proposed by U.S. Pat. No. 5,131,801 to Melanson, wherein a tilt sensor and display panel are used. However, the Melanson approach requires a power source, is costly, and adds a further cable to the forklift. Still other approaches are shown in U.S. Pat. No. 3,883,021 to Wilhelm and U.S. Pat. No. 3,049,257 to Bertenshaw. None of these prior approaches have proven entirely satisfactory.
Accordingly, there remains a need for alternative designs of fork level indicating devices, preferably ones that do not rely on electrical power or complex mechanical linkages.